xref: /linux/fs/nfs/callback_proc.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * linux/fs/nfs/callback_proc.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFSv4 callback procedures
7  */
8 #include <linux/nfs4.h>
9 #include <linux/nfs_fs.h>
10 #include <linux/slab.h>
11 #include <linux/rcupdate.h>
12 #include "nfs4_fs.h"
13 #include "callback.h"
14 #include "delegation.h"
15 #include "internal.h"
16 #include "pnfs.h"
17 #include "nfs4session.h"
18 #include "nfs4trace.h"
19 
20 #ifdef NFS_DEBUG
21 #define NFSDBG_FACILITY NFSDBG_CALLBACK
22 #endif
23 
24 __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
25 			     struct cb_getattrres *res,
26 			     struct cb_process_state *cps)
27 {
28 	struct nfs_delegation *delegation;
29 	struct nfs_inode *nfsi;
30 	struct inode *inode;
31 
32 	res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
33 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
34 		goto out;
35 
36 	res->bitmap[0] = res->bitmap[1] = 0;
37 	res->status = htonl(NFS4ERR_BADHANDLE);
38 
39 	dprintk_rcu("NFS: GETATTR callback request from %s\n",
40 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
41 
42 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
43 	if (inode == NULL)
44 		goto out;
45 	nfsi = NFS_I(inode);
46 	rcu_read_lock();
47 	delegation = rcu_dereference(nfsi->delegation);
48 	if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
49 		goto out_iput;
50 	res->size = i_size_read(inode);
51 	res->change_attr = delegation->change_attr;
52 	if (nfsi->npages != 0)
53 		res->change_attr++;
54 	res->ctime = inode->i_ctime;
55 	res->mtime = inode->i_mtime;
56 	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
57 		args->bitmap[0];
58 	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
59 		args->bitmap[1];
60 	res->status = 0;
61 out_iput:
62 	rcu_read_unlock();
63 	iput(inode);
64 out:
65 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
66 	return res->status;
67 }
68 
69 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
70 			    struct cb_process_state *cps)
71 {
72 	struct inode *inode;
73 	__be32 res;
74 
75 	res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
76 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
77 		goto out;
78 
79 	dprintk_rcu("NFS: RECALL callback request from %s\n",
80 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
81 
82 	res = htonl(NFS4ERR_BADHANDLE);
83 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
84 	if (inode == NULL)
85 		goto out;
86 	/* Set up a helper thread to actually return the delegation */
87 	switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
88 	case 0:
89 		res = 0;
90 		break;
91 	case -ENOENT:
92 		res = htonl(NFS4ERR_BAD_STATEID);
93 		break;
94 	default:
95 		res = htonl(NFS4ERR_RESOURCE);
96 	}
97 	trace_nfs4_recall_delegation(inode, -ntohl(res));
98 	iput(inode);
99 out:
100 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
101 	return res;
102 }
103 
104 #if defined(CONFIG_NFS_V4_1)
105 
106 /*
107  * Lookup a layout by filehandle.
108  *
109  * Note: gets a refcount on the layout hdr and on its respective inode.
110  * Caller must put the layout hdr and the inode.
111  *
112  * TODO: keep track of all layouts (and delegations) in a hash table
113  * hashed by filehandle.
114  */
115 static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp, struct nfs_fh *fh)
116 {
117 	struct nfs_server *server;
118 	struct inode *ino;
119 	struct pnfs_layout_hdr *lo;
120 
121 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
122 		list_for_each_entry(lo, &server->layouts, plh_layouts) {
123 			if (nfs_compare_fh(fh, &NFS_I(lo->plh_inode)->fh))
124 				continue;
125 			ino = igrab(lo->plh_inode);
126 			if (!ino)
127 				continue;
128 			spin_lock(&ino->i_lock);
129 			/* Is this layout in the process of being freed? */
130 			if (NFS_I(ino)->layout != lo) {
131 				spin_unlock(&ino->i_lock);
132 				iput(ino);
133 				continue;
134 			}
135 			pnfs_get_layout_hdr(lo);
136 			spin_unlock(&ino->i_lock);
137 			return lo;
138 		}
139 	}
140 
141 	return NULL;
142 }
143 
144 static struct pnfs_layout_hdr * get_layout_by_fh(struct nfs_client *clp, struct nfs_fh *fh)
145 {
146 	struct pnfs_layout_hdr *lo;
147 
148 	spin_lock(&clp->cl_lock);
149 	rcu_read_lock();
150 	lo = get_layout_by_fh_locked(clp, fh);
151 	rcu_read_unlock();
152 	spin_unlock(&clp->cl_lock);
153 
154 	return lo;
155 }
156 
157 static u32 initiate_file_draining(struct nfs_client *clp,
158 				  struct cb_layoutrecallargs *args)
159 {
160 	struct inode *ino;
161 	struct pnfs_layout_hdr *lo;
162 	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
163 	LIST_HEAD(free_me_list);
164 
165 	lo = get_layout_by_fh(clp, &args->cbl_fh);
166 	if (!lo)
167 		return NFS4ERR_NOMATCHING_LAYOUT;
168 
169 	ino = lo->plh_inode;
170 	spin_lock(&ino->i_lock);
171 	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
172 	    pnfs_mark_matching_lsegs_invalid(lo, &free_me_list,
173 					&args->cbl_range))
174 		rv = NFS4ERR_DELAY;
175 	else
176 		rv = NFS4ERR_NOMATCHING_LAYOUT;
177 	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
178 	spin_unlock(&ino->i_lock);
179 	pnfs_free_lseg_list(&free_me_list);
180 	pnfs_put_layout_hdr(lo);
181 	iput(ino);
182 	return rv;
183 }
184 
185 static u32 initiate_bulk_draining(struct nfs_client *clp,
186 				  struct cb_layoutrecallargs *args)
187 {
188 	int stat;
189 
190 	if (args->cbl_recall_type == RETURN_FSID)
191 		stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
192 	else
193 		stat = pnfs_destroy_layouts_byclid(clp, true);
194 	if (stat != 0)
195 		return NFS4ERR_DELAY;
196 	return NFS4ERR_NOMATCHING_LAYOUT;
197 }
198 
199 static u32 do_callback_layoutrecall(struct nfs_client *clp,
200 				    struct cb_layoutrecallargs *args)
201 {
202 	u32 res;
203 
204 	dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
205 	if (args->cbl_recall_type == RETURN_FILE)
206 		res = initiate_file_draining(clp, args);
207 	else
208 		res = initiate_bulk_draining(clp, args);
209 	dprintk("%s returning %i\n", __func__, res);
210 	return res;
211 
212 }
213 
214 __be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
215 				  void *dummy, struct cb_process_state *cps)
216 {
217 	u32 res;
218 
219 	dprintk("%s: -->\n", __func__);
220 
221 	if (cps->clp)
222 		res = do_callback_layoutrecall(cps->clp, args);
223 	else
224 		res = NFS4ERR_OP_NOT_IN_SESSION;
225 
226 	dprintk("%s: exit with status = %d\n", __func__, res);
227 	return cpu_to_be32(res);
228 }
229 
230 static void pnfs_recall_all_layouts(struct nfs_client *clp)
231 {
232 	struct cb_layoutrecallargs args;
233 
234 	/* Pretend we got a CB_LAYOUTRECALL(ALL) */
235 	memset(&args, 0, sizeof(args));
236 	args.cbl_recall_type = RETURN_ALL;
237 	/* FIXME we ignore errors, what should we do? */
238 	do_callback_layoutrecall(clp, &args);
239 }
240 
241 __be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
242 				  void *dummy, struct cb_process_state *cps)
243 {
244 	int i;
245 	__be32 res = 0;
246 	struct nfs_client *clp = cps->clp;
247 	struct nfs_server *server = NULL;
248 
249 	dprintk("%s: -->\n", __func__);
250 
251 	if (!clp) {
252 		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
253 		goto out;
254 	}
255 
256 	for (i = 0; i < args->ndevs; i++) {
257 		struct cb_devicenotifyitem *dev = &args->devs[i];
258 
259 		if (!server ||
260 		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
261 			rcu_read_lock();
262 			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
263 				if (server->pnfs_curr_ld &&
264 				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
265 					rcu_read_unlock();
266 					goto found;
267 				}
268 			rcu_read_unlock();
269 			dprintk("%s: layout type %u not found\n",
270 				__func__, dev->cbd_layout_type);
271 			continue;
272 		}
273 
274 	found:
275 		if (dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE)
276 			dprintk("%s: NOTIFY_DEVICEID4_CHANGE not supported, "
277 				"deleting instead\n", __func__);
278 		nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
279 	}
280 
281 out:
282 	kfree(args->devs);
283 	dprintk("%s: exit with status = %u\n",
284 		__func__, be32_to_cpu(res));
285 	return res;
286 }
287 
288 /*
289  * Validate the sequenceID sent by the server.
290  * Return success if the sequenceID is one more than what we last saw on
291  * this slot, accounting for wraparound.  Increments the slot's sequence.
292  *
293  * We don't yet implement a duplicate request cache, instead we set the
294  * back channel ca_maxresponsesize_cached to zero. This is OK for now
295  * since we only currently implement idempotent callbacks anyway.
296  *
297  * We have a single slot backchannel at this time, so we don't bother
298  * checking the used_slots bit array on the table.  The lower layer guarantees
299  * a single outstanding callback request at a time.
300  */
301 static __be32
302 validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
303 {
304 	struct nfs4_slot *slot;
305 
306 	dprintk("%s enter. slotid %u seqid %u\n",
307 		__func__, args->csa_slotid, args->csa_sequenceid);
308 
309 	if (args->csa_slotid >= NFS41_BC_MAX_CALLBACKS)
310 		return htonl(NFS4ERR_BADSLOT);
311 
312 	slot = tbl->slots + args->csa_slotid;
313 	dprintk("%s slot table seqid: %u\n", __func__, slot->seq_nr);
314 
315 	/* Normal */
316 	if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
317 		slot->seq_nr++;
318 		goto out_ok;
319 	}
320 
321 	/* Replay */
322 	if (args->csa_sequenceid == slot->seq_nr) {
323 		dprintk("%s seqid %u is a replay\n",
324 			__func__, args->csa_sequenceid);
325 		/* Signal process_op to set this error on next op */
326 		if (args->csa_cachethis == 0)
327 			return htonl(NFS4ERR_RETRY_UNCACHED_REP);
328 
329 		/* The ca_maxresponsesize_cached is 0 with no DRC */
330 		else if (args->csa_cachethis == 1)
331 			return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
332 	}
333 
334 	/* Wraparound */
335 	if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
336 		slot->seq_nr = 1;
337 		goto out_ok;
338 	}
339 
340 	/* Misordered request */
341 	return htonl(NFS4ERR_SEQ_MISORDERED);
342 out_ok:
343 	tbl->highest_used_slotid = args->csa_slotid;
344 	return htonl(NFS4_OK);
345 }
346 
347 /*
348  * For each referring call triple, check the session's slot table for
349  * a match.  If the slot is in use and the sequence numbers match, the
350  * client is still waiting for a response to the original request.
351  */
352 static bool referring_call_exists(struct nfs_client *clp,
353 				  uint32_t nrclists,
354 				  struct referring_call_list *rclists)
355 {
356 	bool status = 0;
357 	int i, j;
358 	struct nfs4_session *session;
359 	struct nfs4_slot_table *tbl;
360 	struct referring_call_list *rclist;
361 	struct referring_call *ref;
362 
363 	/*
364 	 * XXX When client trunking is implemented, this becomes
365 	 * a session lookup from within the loop
366 	 */
367 	session = clp->cl_session;
368 	tbl = &session->fc_slot_table;
369 
370 	for (i = 0; i < nrclists; i++) {
371 		rclist = &rclists[i];
372 		if (memcmp(session->sess_id.data,
373 			   rclist->rcl_sessionid.data,
374 			   NFS4_MAX_SESSIONID_LEN) != 0)
375 			continue;
376 
377 		for (j = 0; j < rclist->rcl_nrefcalls; j++) {
378 			ref = &rclist->rcl_refcalls[j];
379 
380 			dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
381 				"slotid %u\n", __func__,
382 				((u32 *)&rclist->rcl_sessionid.data)[0],
383 				((u32 *)&rclist->rcl_sessionid.data)[1],
384 				((u32 *)&rclist->rcl_sessionid.data)[2],
385 				((u32 *)&rclist->rcl_sessionid.data)[3],
386 				ref->rc_sequenceid, ref->rc_slotid);
387 
388 			spin_lock(&tbl->slot_tbl_lock);
389 			status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
390 				  tbl->slots[ref->rc_slotid].seq_nr ==
391 					ref->rc_sequenceid);
392 			spin_unlock(&tbl->slot_tbl_lock);
393 			if (status)
394 				goto out;
395 		}
396 	}
397 
398 out:
399 	return status;
400 }
401 
402 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
403 			      struct cb_sequenceres *res,
404 			      struct cb_process_state *cps)
405 {
406 	struct nfs4_slot_table *tbl;
407 	struct nfs_client *clp;
408 	int i;
409 	__be32 status = htonl(NFS4ERR_BADSESSION);
410 
411 	clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
412 					 &args->csa_sessionid, cps->minorversion);
413 	if (clp == NULL)
414 		goto out;
415 
416 	tbl = &clp->cl_session->bc_slot_table;
417 
418 	spin_lock(&tbl->slot_tbl_lock);
419 	/* state manager is resetting the session */
420 	if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
421 		spin_unlock(&tbl->slot_tbl_lock);
422 		status = htonl(NFS4ERR_DELAY);
423 		/* Return NFS4ERR_BADSESSION if we're draining the session
424 		 * in order to reset it.
425 		 */
426 		if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
427 			status = htonl(NFS4ERR_BADSESSION);
428 		goto out;
429 	}
430 
431 	status = validate_seqid(&clp->cl_session->bc_slot_table, args);
432 	spin_unlock(&tbl->slot_tbl_lock);
433 	if (status)
434 		goto out;
435 
436 	cps->slotid = args->csa_slotid;
437 
438 	/*
439 	 * Check for pending referring calls.  If a match is found, a
440 	 * related callback was received before the response to the original
441 	 * call.
442 	 */
443 	if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
444 		status = htonl(NFS4ERR_DELAY);
445 		goto out;
446 	}
447 
448 	memcpy(&res->csr_sessionid, &args->csa_sessionid,
449 	       sizeof(res->csr_sessionid));
450 	res->csr_sequenceid = args->csa_sequenceid;
451 	res->csr_slotid = args->csa_slotid;
452 	res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
453 	res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
454 
455 out:
456 	cps->clp = clp; /* put in nfs4_callback_compound */
457 	for (i = 0; i < args->csa_nrclists; i++)
458 		kfree(args->csa_rclists[i].rcl_refcalls);
459 	kfree(args->csa_rclists);
460 
461 	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
462 		cps->drc_status = status;
463 		status = 0;
464 	} else
465 		res->csr_status = status;
466 
467 	trace_nfs4_cb_sequence(args, res, status);
468 	dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
469 		ntohl(status), ntohl(res->csr_status));
470 	return status;
471 }
472 
473 static bool
474 validate_bitmap_values(unsigned long mask)
475 {
476 	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
477 }
478 
479 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
480 			       struct cb_process_state *cps)
481 {
482 	__be32 status;
483 	fmode_t flags = 0;
484 
485 	status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
486 	if (!cps->clp) /* set in cb_sequence */
487 		goto out;
488 
489 	dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
490 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
491 
492 	status = cpu_to_be32(NFS4ERR_INVAL);
493 	if (!validate_bitmap_values(args->craa_type_mask))
494 		goto out;
495 
496 	status = cpu_to_be32(NFS4_OK);
497 	if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
498 		     &args->craa_type_mask))
499 		flags = FMODE_READ;
500 	if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
501 		     &args->craa_type_mask))
502 		flags |= FMODE_WRITE;
503 	if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
504 		     &args->craa_type_mask))
505 		pnfs_recall_all_layouts(cps->clp);
506 	if (flags)
507 		nfs_expire_unused_delegation_types(cps->clp, flags);
508 out:
509 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
510 	return status;
511 }
512 
513 /* Reduce the fore channel's max_slots to the target value */
514 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
515 				struct cb_process_state *cps)
516 {
517 	struct nfs4_slot_table *fc_tbl;
518 	__be32 status;
519 
520 	status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
521 	if (!cps->clp) /* set in cb_sequence */
522 		goto out;
523 
524 	dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
525 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
526 		args->crsa_target_highest_slotid);
527 
528 	fc_tbl = &cps->clp->cl_session->fc_slot_table;
529 
530 	status = htonl(NFS4_OK);
531 
532 	nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
533 	nfs41_server_notify_target_slotid_update(cps->clp);
534 out:
535 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
536 	return status;
537 }
538 #endif /* CONFIG_NFS_V4_1 */
539